Thermal conductivities of one-dimensional anharmonic/nonlinear lattices: renormalized phonons and effective phonon theory

TL;DR

This paper investigates heat transport in one-dimensional nonlinear lattices, identifying renormalized phonons as energy carriers and developing an effective phonon theory that accurately predicts thermal conductivity scaling behaviors.

Contribution

It introduces an effective phonon theory for nonlinear lattices and validates its predictions through numerical simulations, advancing understanding of energy transport mechanisms.

Findings

Effective phonon theory predicts thermal conductivity scaling exponents.

Numerical simulations confirm the theory's quantitative accuracy.

Renormalized phonons are the primary energy carriers in these systems.

Abstract

Heat transport in low-dimensional systems has attracted enormous attention from both theoretical and experimental aspects due to its significance to the perception of fundamental energy transport theory and its potential applications in the emerging filed of phononics: manipulating heat flow with electronic anologs. We consider the heat conduction of one-dimensional nonlinear lattice models. The energy carriers responsible for the heat transport have been identified as the renormalized phonons. Within the framework of renormalized phonons, a phenomenological theory, effective phonon theory, has been developed to explain the heat transport in general one-dimensional nonlinear lattices. With the help of numerical simulations, it has been verified that this effective phonon theory is able to predict the scaling exponents of temperature-dependent thermal conductivities quantitatively and consistently.